Key sender



G. R. PAUL. 2,930,354

m sENDER 5 sheets4sneet 1 QOL? oJ.

March 29, 1960 .Filed Dec. 23, 1957 G. R. PAUL KEY SENDER March 29, 1960 5 Sheets-Sheei'l 2 Filed Dec. 23, 1957 (39 loo K AAA H L Il H jl Mmh 29, 1960 G. R. PAUL 2,930,854

KEY SENDER Filed nec. 23, 1957 L 5 sheets-sheet s F/aa 8L Q: l l A l TJ T; L L M QBLWF@ 13"' N' 9 il t | 'AVA' March 29, 1960 G. R. PAUL 2,930,854

KEY SENDER Filed Dec 25, 1957 5 Sheets-Sheet 4 F IG. 4 a

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G. R. PAUL KEY SENDER March 29, 1960 5 Sheets-Sheet 5 Filed Dec. 23, 1957 7 L R N kv m mmc I l l l l I l l l l |...l N L NEU P ommm CND YWV w upm H 2 a MIIWW /fmmu R R l 2 G T C L R y s www m m m l'llll'loull IIIF u l i SIIIIIII l l I l Il S I? M K s A R L 6 m 5` s l 2 9/ A 7 wl -illi -i i D V ,Mmmm 1 x n @27+ fil J 7 3 3 Sllll. .I ,1| \..|I...|| I l l I l l I l l l I l I I I I l l w/ 5 r m lill! Il R w l .d u R Jv 0 f. lll J 5 2 MI. 6. i3 4 56 L H Q... 20E. mzoramd o FF KEYSEND1':R vv Gerald R. Paul, Webster, N.Y., assigner to General `Dynamics Corpoi'ation,y Rochester, N.Y., a corporation of'Delaware Application December 23, 19157; Serial 74,48i6 12 Ciai'ms'.' (Cl. 17g-m90)A This invention relates to signaling devices and Tparticu larly to means for transmitting trains of digital pulses useful in telecommunicationsystems. s 'l An object of thev invention is to provide 'means for automatically timing andtransmitting a plurality of digital trains of pulses including both the pulses of the, various trains and the interdigit timeintervals between said trains.

.Another Object Of ,this investies is Vte Previdelimitins means whereby the device may send anynumber of digital trains of pulsesgbut, will always come to a halt and pro duce a signal that all of and only the numbers written up have been transmitted. Y u l t The invention resides primarilyV in lan electronic device s controlled by a simple set of digithkeys and a number of controlling relays to vbe connected toma .telephone substation circuit in place of the ubiquitous vdial.. lt is e spe. ciallfy useful in situations where an operatoris provided Witndinlins, Ineens but. may bensed., elsewhere- Y. It. p.- eretes on the` principle of ,translating the digits telve transmitted to expressions which may becounted down freni. sneh n.1` expression representing .s digit'. te a given standard expression, which beingV lreached constitutes a signal that the operation is complete. J v i.

The invention is characterized by the use of a n1eans for counting down` a fictitious number between eachv digit- :al ltransmission fornieasuringV what is known asl interdisif. time, `Consequently.the device is. ,characterized-by the use of a pulsing relay which periodically operates over the complete dialing period and which not only controls the counting of the number of pulses for the completer number consisting of a plurality of digits bu t alsoon-l trols the counting of the number of pulses foreach tictitious interdigt timing digit interpolated in. such transmined number.

s Bv;A this means. the said. pulsinsreley .may be, operated from a constantly operating multivibrator which may be precisely adjusted to provide the proper periodicity of vpulsing and the proportionate division of each cycleinto the proper malte and break intervals. By; this means the advantages of'a constantlyrunning' device overa frequently stopping and startingideyice mayibe gained.

The invention is furt he r characterized by the use of counting in and countingoutjchains h avllgfy unique mutuel control whereby anindenitle A,number .of .digits may be stored and then transmitted, that is,-on1y thejsame number of digits will be transmitted as have been stored.

f A single digit may be stored and then transmitted out,

or a complete telephone designationtof ten (for direct distance dialing) or of seven (for localcalling) digits maybe handled, f I

A feature of the invention is the use of means controlled by the counting in `chain to constitute an enabling signal in lthe ountingfout chain whereby' the number of transmitted digits is limited strictlyto the number of record digits. In accordance with vthis feature thepoint rf :l1`e 'dfa l `ngv the ounting"'in chain" becomes a limiting sigaar iff'thecountingout chain;

- ingly four' triggers are p'rm/ioel-.` KATo4 this stiingoflzf, ul-

trigger circuits, and ysince the counting-'down proces'salwaysends -with a change in the fourth trigger,v another ice A feature of the inventionis a transmitting register into which the expression of a digit'tobe dialed is introduced andl which may be counted down to ansexpressiou ,Gsmstitutinga stop signal. This register consistsessentially f a chain of trigger circuits varranged in ay'binarycircuit whereby the first in line `v being constantly subjected to a train of incoming pulses, controls the others in accordancewith theprinciplesl of binary addition. t .Since v four suchl triggers will serve torepresent more thanuthe ten digits used for telephone number designations,- accorltrigger circuit is added'to the chain to countthe odd and even number of count down operations. The odd numbered' operations represent digits actually transmitted while the evenfrlumbered' yoperations represent fictitious di'gits counted down but not transmitted. v

In accordance with this feature a relay'(DOS.)` is pro4 vided to'respond to said' odd and evenY counting trigger to control the readout chain and which, upon the release thereof after an even count down operation, will llct vr to advance such chain, the said relay being operated at the endof an odd countdown operationand remainin'g'operated*l during the following even count down operation.

Another feature of the invention is an end of sending relay (EOS)V which responds when the counting out chain catches up with the counting in chain' and which thereupon terminates operations of the device including the further operation of said constantly operating multivibrator and its controlled pulse relay.

Another feature of the invention is a; reorder means by which the train of switches se't'bly' a sender release operation may be released`withou't wiping out the record established inA thel registers ofthe y device whereby 4' anotl'let' dialing operation maybe performed without the necessity of writing up anewv the digits of the called number.

lln accordance withthis f eature and ,sincelhe openaitions stopped by the end of sending relay do net .allow an interdigit count to be made after the transmission of the lastdigit, and consequently the oddeven count trigger' id left'in its binary 1'ckaiidition,"'the saidreo X iri- Acldes "meansto reset the saidoddeven count r1 f its'binary ze'rocon'dition ywhereby it isset into cond to properly count the iirst digit transmitted followiiig suehy reorder operation. 1 f n f Other features will appear hereinafter. l

The drawings consist of ve sheets having seven figures as follows:

Fig. 1 is a schematic Ycircuit diagram showing the circuitry within the key box placed at thedisposal of the subscriber, including the tendigital keys, the, sender rrelease'key, the reorder key/,fand thel three signall p s as wellas the neonr tube lamp's'employed toA transl e the vdecimal value ofthedigital keys andnto tr t the binary representations over the l, 2', 4 and 8 bit leading to the various registers; .y e

Fig. 2 is a schematicl circuit` diagram showing the countingin chain, the l bit register sections of .four y (representativ e)' registersv aid the l bitv trigger Ycircuit of thel transmitting: register;

*Patented Mar. 29, 19,60y

employed to constantly and periodically operate the pulsing relay at a precisely controlled rate;

Fig. 6 is a block diagram on the same sheet as Fig. 1, indicating the arrangement of Figs. 1 to 5 to form a complete circuit diagram, and;

Fig. 7 is a schematic circuit diagram of a conventional telephone substation circuit to which either a conventional dial or the device of the present invention may be connected.l

The prior art Two particular examples of the prior art are herein noted for the purpose of inclusion by reference:

IPatent 2,854,521, September 30, 1958, Morris et al.

Ser. No. 641,657, February 21, 1957, Fisher, Jr.

The first of these shows a sender responsive to dial pulses for producing outgoing dial pulses, whereas the second shows the use of neon tubes for diode purposes and which is incorporated in the first as a part thereof.

The sender of the present invention has many circuits in common with the Morris et al. dial to dial sender including particularly the manner of registering a digit -as the tifteens complement of one less than the value of the digit whereby the outgoing train of pulses is produced by counting down such an expression until a particular code which acts as a signal is obtained.

By way of example, and since it forms an important part of the present invention, the interdigit time is considered to be six pulse lengths and therefore as the sending of a telephone number digit is completed, the register which is counted down is reset to the inverted value of six minus one. In the binary code six is written vas and. five is written as and the s complement of live is written as Since reading is usually from left to right, this is represented as .The counting down consists of successively adding 1 to the left hand place, whereby the six successively added binary digits successively produce the following representations: 1 i

After 1st added binary digit 1 1 0 l After 2nd added binary digit 0 0 1 l After 3rd added binary digit 1 0 1 1 After 4th added binary digit 0 1 1 l After 5th added binary digit 1 1 1 1 After 6th added binary digit 0 0 0 O Thus, the counting down process starts with the entry into the outgoing register of the ifteens complement of one less than the number to be dialed and ends with the outgoing register being completely cleared and ready for the next operation.

The circuitry The circuitry shown in schematic form in Figs. 1 to 5 inclusive represents a key sender which may be connected to a conventional telephone substation circuit in place of the conventional dial. In operation, the subscriber or the operator, where this may be used by such a person, will rst operate the conventional hook switch and then Write up the number of the called line, digit by digit by means of the keys shown in Fig. 1. Each operation of such a key will set a register and advance the incoming chain so that the next register will be enabled. When the number is completely written up, the subscriber or the operator will depress the sender release key where-l `and reset the device to dial the same number again, the

record written up previously being retained and the outgoing chain being recycled.

If the subscriber wishes to release the dialed connection and the stored number, she depresses the hook switch or its equivalent whereby the record in the registers may be released so that a new number may be keyed.

For these purposes a number of conventional relays are employed as shown in Fig. 5 and which may be shortly described as follows.

SR is the sender release relay which is operated by the sender release key after the operator or subscriber has written up the wanted number and which when operated functions to start the sending of the outgoing trains of pulses.

REO is the reorder relay which may be operated by the reorder key to recycle the device so that a recorded telephone number may be dialed without the necessity of writing up the number on the digital keys again.

EOS is the end of sending relay and is arranged to operate when the proper number of trains of outgoing pulses have been sent.

DOS is the dial out stop relay which operates at the end of each train of pulses which vare transmitted, that is when the record transferred to the out pulse register has been completely counted down and the binary 8 Iregistration changes from binary 1 to binary 0 and releases at the end of each train of pulses representing the ctitious digits,

OKS is the OK to start relay which becomes operated when all conditions necessary to proper operation have been met and it is proper for the automatic operations to begin.

SIT is the start interdigit timing relay which becomes operated after each train of pulses has been spent to start the counting down of the interdigit time. Since the pulse relay is continuously operated by a continuously operating multivibrator and the interdigi time is taken to be equal to six pulse lengths, the SIT relay operates to reset the out pulse register to a fictitious six value so that this must then be counted down before the next digit is transferred thereto.

SS is the start relay which becomes active as soon as the hook switch has been operated and which acts to activate the device of the present invention which substitutes for the conventional dial.

SS1 and SSZ are slave relays which faithfully follow the SS relay, SS1 acting to establish a supply of signal battery and a priming signal and SS2 acting to establish a main and a signal ground.

PLS is the pulse relay which continuously operates under control of a multivibrator adjusted to the proper periodicity for dialing and the proper proportional make and break timing.

Operation When the hook switch 1 of the telephone is closed in the position shown, the conventional line current will now over the ring of the line, through the circuitry of the telephone set consisting principally of the transmitter 2 and coil 3, to the L1 terminal, thence through the armature 4 and back contact of the REO relay 5, the winding of the SS relay 6, the armature 7 and the back contact of the PLS relay 8, the back contact and armature 9 of the SSI relay 10 to ground. While another ground may sbc gfound leading backover ,the L2..cor 1ductor to the tip .ofthe line, this more solid .ground is temporarily pro- A,vided to insure the promptoperation ofthe SS .relay 6.

:'-Ihe SS relay `causes the immediate operation of its sslaye, the SSI relay 1.6 andthis in turn causes theoperaetioniof the SS.2 relay 11.

The SSI .relay llt) applies battery to the signal .battery terminal 12 here shown `as a circle enclosing the .letter ,S :and vwhich is permanently connected to many other .points in the circuitry .such as the anodes of the switching itubes like'the first tube 13 of the input counting vchain (Fig. .2). lThis application v.of battery to terminal 12 .also acts through condenser 14 to transmit a single `pulse .to :the priming terminal 1 5, which again is connected yto4 manyfother points in thecireuitry such as the terminal -1 6,*-wher e it.pass es a `pulse through the neon lamp 17 and "the .condenser 1-8 to the trigger terminal or grid of vftl 1 e; tu'be13. This priming pulse isalso passed to the ffounbinary y tubes ofthe f our ip yiiops comprising the gout-going digit Vregister to s et this register to 0000.

The SSZ relay 1 1, places ,a Vground on theconductor .19to'enablethesender,release ykey 20 and the reorder key 21. At the same time itplaces aground on the signal ground terminal 22 which again will be Vfound dupliu cat-ed at all the terminals ofthe vneon register lamps, suchastheiterminal 23for the lamp 24, whereby .each ofl the registers is vmade ready for operation.

Upontheremoval of the low resistance ground con- .ffnectionfto the back contact of ar-mature y9 of `the SSI re l ay,1 0, andprovidingthedirect ground to the tip -has .beenremoved in the central oice line circuit by the :proper extension o f the circuit to a first selector, a fsutiicient current from the telephone line circuit will QW. throughy theresistor 2 5.and the upper windingof the O KS relay 2,6 to move itssensitiveX armature so that `this relay nowbecomes locked through its lower winding to the ground supplied by-theSS relay. 6. The OKS .relai/now becomes fully operated and disconnects its upper Winding from the Ll circuit. At 'the same time the ground supplied for the holding of the lOKS relay.

,126. is supplied Aover conductor 27 to the White signal lamp ,28,10 notify the subscriberuthat'the sender is idle and thatgitis QK -to send, that is, the digit ,keys may be operated.

.Let it ynow be assumedthat the subscriber operates the number 7 digit key v29. This vwill connect battery .-.over:the armature3t andback contact of the SR relay ..31, the back contact and armature 32 of the EOS relay i333 conductor 34 through the closed contacts of the 1 .t.to.7 digit keys to the front; contact of the `digit key v2,9c

.and thencel to the neon lamps `3S and .36 to the vWires Vv37,and 38 respectively; Tracing ,wire .'37, we see that a connection is made through a resistor .39 and a resistor -AQ /togro und whereby the neon lamp 35 will conduct .and -.threby apply a raised potential to the wire 41. .wage shape ofv the pulse applied to wire 41 is` shown schematically in Fig. 2 and this indicates .that as the k ey .29 is operateda pulse, through the .047 condenser .bridged `about resistor 39 is first delivered to the Wire 41 `jandthereafter until the key `29 is o a steady potential as limitedby the resistor 39 is applied thereto. The pulse Yisgreat enough to tire any lamps such as the gate 43 Eandthe register lamp Z4, but the potential maintained .onvthiswirefil after the initial pulse and until the key is-v'released is insuihcient to iiresuch lamps or tubes so -rthat-since `the steeringain chain is advanced long before .the.subscriber `releases lthe key 29such raised potential .iiwilLnot result in the tiring of `a register gatel or lamp in the .next register.

. Ithas heretofore been stated that the tube 13fwas trig- .ifgeredgand .hence its cathodeand therefore the wire 42 n are ataraised potential. This potential `by-itself is not sufficient to re theneon lamp. 43 but when the .potential -tpulseonfwire 413s transmitted, aI pulse through condenser Atiaapplied ta-.thalamn-Aud .it prisssisra.puleitluc 1ishv .the vcondenser 45 `to -iire ther'lamp 724 which ,th

.ground on terminal 23 is removed.

' raising of the potential on wire 41 theneon lamp 5 1 will .S6 in the steering in chain. Since the tube 13 is c ond be tired and a pulse will be produced in condenser SH2 and transmitted over Wire 53 to trigger .the tube Thisft'ubie res momentarily and therefore produces a positive pulse on wire 55. The effect of this is .to triggerthe'next'tube ing at this time the gate lamp 57 is in a eonditionto pulse from the wire 55 over the condenser 58, through t L gate 57 and the condenser 59 to the trigger vf tube v'56. As tube 56 tires the pulse produced incondensenacts to'quench the tube 13 so thatthe next incomngsignalon wire 41 may be used in any one of the .register circuits controlled by the wire .61. in this manner the steeringin .chain .willsuccessively `enable an equal number of registersA to successivelyregister the digits Written up by the subscriber.

Herein, by Way of example, foursuchregisters vare shown and ve tubes in the steering in chain larev shown. The last tube 62 which is fired as the subscriberzreleases the last key, raises the potential on Wire 63't0..enable` .the gate lamp f64 so that under normal conditions whenfthe steering out chain has advanced tothe firing ofthelast tube 65 a pulse produced thereby through condenser 2.6.6

vwill trigger the end of sending'tube-67 to. operatethe end of sending EOS relay 33.

It may be brought out at this point thatl if the subscriber writes up but 'a single digit the potential on wirer .will be raised to enable the gate lamp .6 8 so that-thereafter-if the sending is started it will gonofurther than. tosend a single digit, for upon the firing of the,rs't steeringnut tube 69, a pulse over the condenser 7 0. will be transmitted over the gate lamp 68 to trigger the end .of seudilig tube `67.

Thus, when the subscriber has written upthesfullpr even a partial designation he may cause the sending.. t'o

vStart by operating thesender releaseykey=2,.1h.reby

connecting the ground on conductor-19 to conductorll leading to the red signal 1ampf72 and ovenback contacts' and armatures of the EOS relay 33 and :theDO S, relay 73 to the winding of the SRrelay 3l. Thev sender release vrelay 31 operates and shorts 1the transmitter and. receiver of the telephone set for better transmissionoftheroutgoing pulses and to prevent the subscriber from hearing such pulses and through its ,armature Y.74enables @the multivibrator by interconnecting theemitter of transistor with the resistor 76 leading to theemitter ofxtrans'ijstor 77 and with the emitter of transistor 78. f The multivibrator including`-the three transistors 75,

V77 and 78 is conventional in its operation and'is adjusted to operate the vPLS pulsing relay ata regular ,rat e by Way of example, at l0 pulses per second ata 4010,60 maker-break ratio. Thus, upon the operation of the sender release key 2t) ythe pulsing .relay Will s tartto operate at a regular rate and will continue to sooperalte until both the EOS relay 33 and the D OS relaygt'lhaye been operated and the SR relay 31 is thereby released.

Let it be assumed that the subscriber haskeyedfasfull number and that all they registers have.been-=lled. Then upon the operation of the4 SR relay.` 31,. a vsignal battery .will be extended over an armature and'frnt contact y'of the OKS relay 26, the front contact and Vsensitive X arma- 24.and 46 are aglow as before described.sotthattheneon '15 glow lamp., gates...83 and 84 ..1;espectively....are enable',

`pulses will 4be transmitted over-'conductors 85 and 86 `respectively to trigger the tubes 87 and 88 respectively,

thus writing up in the transmitting register the value 1001.

It may now be noted that the PLS relay 8 will continuously apply a train of pulses to the conductor 89, leading to the ip flop composed of tubes 90 and 87, through the condenser 91. This will count down the 'registration 1001 set in this transmitting register, producing the following results.

Thus it will be seen that seven pulses are counted and that on each such pulse the line circuit to the telephone is opened by the armature 7 of the PLS relay 8. The SS relay 6 is slow to release so that it does not release on any one of these pulses.

As the tube 88 of the 8 bit flip iiop is quenched a pulse is transmitted over the common trigger wire 92 to cause the triggering of tube 93, which thereupon causes the operation of the DOS relay 73. This is the dial out stop relay whose function is to stop the transmission of pulses over the line. The operation of this relay therefore establishes a circuit from ground to the conductor 94 and thereupon through a back contact and armature of the PLS relay 8 to the winding of the SIT relay 95, which establishes a bridge about the armature 7 and back contact ofthe PLS relay 8. Thus, as soon as the digit 7 has been transmitted, the SIT (start interdigit timing) relay 95 is operated to keep the continued pulsing of the PLS relay from aifecting the line.

Upon the operation of the SIT relay 95, battery is applied to conductor 96 for the purpose of triggering tubes 97 and 88 thus writing up the binary complement of the ctitious value 6 (0101) in the transmitting register, which must now be counted down as before. When this operation is complete the tube 98 will be triggered and the DOS relay 73 will be released.

Upon the operation of the DOS relay, conductor 99 is connected to ground through 100K and this discharges the condenser 100 so that after the interdigit six pulses are counted and the DOS relay releases, battery will again be placed on this conductor 99. This will trigger the second tube 101 in the counting out chain. The operation of tube 101 transfers the registration in the second storage register to the transmitting register as before described so that the next digit may now be transmitted. Upon this release of the DOS relay the SIT relay is released to take the bridge oi the pulsing contacts.

It may be noted that the green signal lamp 102 is connected to conductor 94 so that it will indicate the closed condition of the telephone line, winking on each digital pulse transmitted thereover.

When the transmission of the last digit has been completed the EOS relay is operated as before described and this will, in conjunction with the DOS relay 73, open the circuit to the SR relay and stop further circuit operations. If in due time the called party answers, a con version may be held conventionally. During this period the OKS, the DOS, the EOS, the SS, the SSI and SSZ relays will remain in operation. At the end of the conversation, when the hook switch 1 is opened, these relays will release and the circuit will be returned to normal.

Reorder After a complete operation of the device, and before release as above, should the subscriber wish to dial the connection again without having to write up the number, be will momentarily. operate the reorder key 21. This will cause the operation of the REO relay 5, open the connection to L1 and thus drop ol the train of switches. While the SS relay 6 may release if the operation of the reorder key is prolonged, the reorder relay will place a substitute ground on the winding of the SSI relay 9 so that the signal battery and the signal ground are not disturbed and hence the record established in the various registers is not lost. All the other relays excepting SS1 and SSZ are restored and all signal lamps are put out. It will be noted that the plate circuit to tube 67 is opened so that this tube is extinguished and therefore the EOS relay 33 is restored. Tube 98 is primed, whereby tube 93 is extinguished and therefore the DOS relay 73 is released. However, the operation of the REO relay 5, reoperates the SR relay 31, connecting lead to the front contact of the OKS `relay so that sending may begin as soon as the OKS relay 26 operates. As soon as the reorder key 21 is restored to normal the OKS relay 26 and the SS relay 6 will restore and the device will assume that stage of operation reached after the called number had been written up and the SR key operated. The operation will now be in accordance with the previous operation above described.

What is claimed is:

1. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, consisting of a register, means for setting said register to representations of selected digits, means for setting said register to representations of ctitious digits, means for counting down said settings to clear said register. means for transmitting outgoing pulses during and corresponding to said counting down of said selected digits, and means for preventing the transmission of outgoing pulses during said counting down of said fictitious digits and means responsive to said means for counting down selected digits for operating said means for setting said register to representations of fictitious digits.

2. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, comprising a register consisting of a series of binary trigger circuits, means for entering therein selected digits and fictitious digits expressed as 15-(n-1) in binary code where n is equal to a said digit, means for counting down said register consisting of means for repeatedly entering into said register a binary 1 to advance the condition of said register through increasing values to a binary code 0000, said counting down means including a pulsing relay, means for regularly and repeatedly operating said pulsing relay, an outgoing signal circuit controlled by said pulsing relay and means for rendering the control of said pulsing relay over said outgoing signal circuit ineffective during the said counting down of a fictitious digit.

3. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, comprising a register consisting of a series of binary trigger circuits, means for entering therein selected digits and ctitious digits expressed as l5(n1) in binary code where n is equal to a said digit, means for counting down said register consisting of means for repeatedly entering into said register a binary 1 to advance the value of the number registered therein through increasing values to a binary code 0000, said register including in said series an additional binary trigger circuit for exhibiting the odd and even number of times said register has been counted down, said counting down means 1ncluding a pulsing relay, means for regularly and repeatedly operating said pulsing relay, an outgoing signal circuit controlled by said pulsing relay, and means controlled by said additional binary trigger circuit for rendering tbe control of said pulsing relay over said outgoing signal circuit alternately eiective and ineffective responsive to the odd or even count exhibited thereby.

4. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses,

comprising a register consisting of a `series `bf binary trigger circuits, means for entering therein ldigits .selected Sfor transmission and digits employed Vfor timing purposes, each digit being in binaryfcode for 16-n where .n is the said digit, means for clearing said 4register after 'the entry of a digit therein consisting of means for entering thereinto successively and repeatedly a binary l until the said code is reduced to 0000, said register including .in said series an additional trigger circuit for indicating the odd and even number of times said regisf .ter has been counted down to said 0000 representation, said means for clearing said register consisting yof Aa pulsing relay, .a multivibrator for `continuously and repeatedly operating Vsaid Apulsing relay and a SIT,` start interdigit timing, relay responsive `to odd indicationsploduced by said additional trigger circuit for interpolating timing digits vbetween saiddigits selected for transmission, said pulsing Arelay having contacts for .transmitting outgoing signal pulses and said SIT relay yhaving contacts for shunting said pulsing relay transmitting contacts.

5. Asender for controlling the ltransmission vof numbers in the .form-of a series of ytrains yof digital pulses, comprising a .transmitting register consisting of 'a series of binary trigger circuits, .a plurality of storage registers, a steering in chain for successively enabling said storage registers for receiving digits in the binary code of 16-n where n is the said digit, a steering out chain for successively enabling said storage registers for transmission of digits stored therein to said transmitting register, means for simultaneously transmitting digital pulses and entering pulses into said transmitting register to advance the code contained therein to the ending code 0000, means responsive to the said code 0000 for advancing said steering out chain and means controlled by said steering in chain for limiting the operation of said steering out chain to an equal number of steps.

6. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, comprising a transmitting register consisting of a series of binary trigger circuits, a plurality of storage registers, a steering in chain for successively enabling said storage registers for receiving digits in the binary code vof l6-n where n is the said digit, a steering out chain for successively enabling said storage registers for transmission of digits stored therein to said transmitting register, means for simultaneously transmitting digital pulses and entering pulses into said transmitting register to advance the code contained therein to the ending code 0000, means responsive to the said code 0000 for advancing .said steering out chain, means for interpolating timing digits between each said digit transmitted by said transmitting means, means for preventing the transmission of pulses during the counting down of said timing digits and means controlled by said steering in chain for limiting the operation of said steering out chain to an equal number of steps.

7. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, comprising a transmitting register consisting of a series of binary trigger circuits, a plurality of storage registers, a steering in chain for successively enabling said storage registers for receiving digits in the binary code of l6-n where n is the said digit, a steering out chainfor successively enabling said storage registers for transmission of digits stored therein to said transmitting register, means for simultaneously transmitting digital pulses and entering pulses into said transmitting register to advance the code contained therein to the ending code 0000, means responsive to each odd numbered occurrence of said code 0000 for preparing a circuit to advance said steering out chain and responsive to each even numbered occurrence of said code 0000 for advancing said steering out chain,` means responsive to the said advance of said steering out chain to enter the next stored digit into said transmitting register and means responsive to each odd '1D numberedoccurrence -of/said code 0000 for resetting'isaid transmitting register to a fictitious digit constituting interdigit timing digit, means for preventing the transmission of pulses during the counting down of fictitious digits and means controlled by said steering inchainfoi' Vlimiting the operationof said steering out chain '.to'an equal number of steps. f i8. A sender for controlling the transmission of .numbers 2in the form of a series of trains of digital pulses, comprising a transmitting register consisting of va series of binary trigger circuits, a plurality of storage registers, a steering in chain for successively enabling said storage registers for receiving rdigits in the binary code of ll-.n wheren is the said-digit, a steering out chain for successively enabling said storage registers for transmission kof digits stored therein to said transmitting register, means for simultaneously transmitting digital pulses and entering `pulses into said transmitting register to advance vthe code .contained `therein to the ending code 0000, fan .additional trigger circuit in said series of trigger circuits lconstituting said transmitting register to count the odd 'andievenioccurrencesof said .ending code 0000, a sender Y release key for starting the operation 4of said steering .out chain, means .controlled by said steering in chan1for terminating the operation of said steering out chain at j' any given step therein and a reorder key for restarting the operation of said steering out chain whereby a number entered into said storage registers may be transmitted repeatedly. Y

9. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, comprising a transmitting register consisting of a series of binary trigger circuits, a plurality of storage registers, a steering in chain for successively enabling said storage registers for receiving digits in the binary code of. 16-11 where n is the said digit, a steering out chain for succes sively enabling said storage registers for transmission of digits stored therein to said transmitting register, means for simultaneously transmitting digital pulses and entering pulses into said transmitting register to advance the code contained therein to the ending code 0000, an additional trigger circuit in said series of trigger circuits constituting said transmitting register to count the odd and even occurrences of said ending code 0000, means controlled by said additional trigger circuit responsive to the indication of an even count therein to transfer a stored digit to said transmitting register, means further controlled by said additional trigger circuit responsive to the indication of an odd count therein to automatically set said transmitting register to a fictitious value as an interdigit timing digit, means controlled by said last means for preventing the transmission of digital pulses during the said counting down operation from a said fictitious digit, a sender release key for starting the operation of said steering out chain, means controlled by said steering in chain for terminating the operation of said steering out chain at any given step therein and a reorder key for restarting the operation of said steering out chain whereby a number entered into said storage registers may be transmitted repeatedly.

10. A sender for controlling the transmission of numbers in the form of a series of trains of digital pulses, said trains being separated by uniform time intervals, consisting of a transmitting register comprising a series of binary trigger circuits connected in cascade to form a counter, a timing means for operating said counter at a predetermined rate, means for successively and alternately entering into said register representations of regular digitsfor transmission and fictitious digits for marking time constituting said uniform time intervals, said last means being controlled by an additional binary trigger circuit connected in cascade to said trigger circuits forming said counter to indicate the odd and even number of operations of said counter, the entry of each digit, regular or ctitious, being controlled by the completion' of the counting of a preceding digit, 'ctitious or regular, signalled by an operation of said even and odd counter, whereby said transmitting register operates regularly, periodically and constantly until a complete number has been transmitted, and means controlled by said counter for transmitting a digital pulse for each count of a said regular digit.

11, A plurality of bistable trigger circuits connected in cascade to form a binary counter to produce an uninterrupted count of serially related signals in successive groups alternately representing digits for transmission and fictitious digits for marking time, means responsive to the completion of the count of the signals of each said group for entering into said counter the signals for a succeeding group, a dial pulse transmission circuit, means responsive to the counting of the signals constituting said digit for transmission for transmitting over said dial pulse transmission circuit a train of dial pulses and means responsive to the counting of signals constituting said fictitious digit for marking time to exclude dial pulses from said dial pulse transmission circuit and a conlinuously operating timing means to operate said counter at a conventional dial pulse rate.

12. A plurality of bistable trigger circuits connected ifm-cascade toform a binary counter to produce an uninterrupted count of serially related signals in successive groups alternately` representing digits for transmission and fictitious digits for marking time, means responsive to the completion of the count of the signals of each said group for entering into said counter the signals for succeeding group, a dial pulse transmission circuit, means responsive to the counting of the signals constituting said digit for transmission for transmitting over said dial pulse transmission circuit a train of dial pulses and means responsive to the counting of signals constituting a said ctitious digit for marking time to exclude dial pulses from said dial pulse transmission circuit and a free running multivibrator for operating said counter at a predetermined dial pulse rate.

References Cited in the file of this patent UNITED STATES PATENTS Blessing Dec. 7, 1926 2,145,079 Gibson Ian. 24, 1939 2,576,099 Bray Nov. 27, 1951 2,723,312 McGugan Nov. 8, 1955 2,794,976 Faulkner June 4, 1957 

